SPRING Washington Monument ROCK CREEK PARK DC’s 1,754-acre ribbon of green offers numerous trails for hiking and biking, picnic groves, horse stables, a planetarium, tennis courts, a golf course and a historic gristmill. a Japanese-style garden, a French parterre and a Lunar Lawn. Online reservations are required. WASHINGTON.ORG ENID A. HAUPT GARDEN Located outside of the majestic Smithsonian Castle, this beautifully crafted garden blends Victorian and Asian styles, with plenty of benches for relaxation and wondrous water features. HILLWOOD ESTATE, MUSEUM & GARDENS Marjorie Merriweather Post’s estate features a breathtaking outdoor oasis complete with a rose garden, 19